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DLERROR(3P)                POSIX Programmer's Manual               DLERROR(3P)

PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       dlerror - get diagnostic information
SYNOPSIS
       #include <dlfcn.h>
       char *dlerror(void);

DESCRIPTION
       The dlerror() function shall return a null-terminated character  string
       (with  no  trailing  <newline>)  that  describes  the  last  error that
       occurred during dynamic  linking  processing.  If  no  dynamic  linking
       errors  have occurred since the last invocation of dlerror(), dlerror()
       shall return NULL.  Thus, invoking dlerror() a second time, immediately
       following a prior invocation, shall result in NULL being returned.
       The  dlerror()  function  need not be reentrant. A function that is not
       required to be reentrant is not required to be thread-safe.
RETURN VALUE
       If successful,  dlerror()  shall  return  a  null-terminated  character
       string; otherwise, NULL shall be returned.
ERRORS
       No errors are defined.
       The following sections are informative.
EXAMPLES
       The following example prints out the last dynamic linking error:

              ...
              #include <dlfcn.h>

              char *errstr;

              errstr = dlerror();
              if (errstr != NULL)
              printf ("A dynamic linking error occurred: (%s)\n", errstr);
              ...
APPLICATION USAGE
       The  messages  returned by dlerror() may reside in a static buffer that
       is overwritten on each call to dlerror().  Application code should  not
       write  to  this  buffer.  Programs wishing to preserve an error message
       should make their own copies of that message. Depending on the applica-
       tion environment with respect to asynchronous execution events, such as
       signals or other asynchronous computation sharing  the  address  space,
       conforming  applications  should use a critical section to retrieve the
       error pointer and buffer.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       dlclose(),  dlopen(),  dlsym(),  the   Base   Definitions   volume   of
       IEEE Std 1003.1-2001, <dlfcn.h>
COPYRIGHT
       Portions  of  this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003  by  the  Institute  of
       Electrical  and  Electronics  Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained  online
       at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                  2003                          DLERROR(3P)